It is known to use cationic surfactants in detergent compositions. For example, GB 2040990A describes granular detergent compositions comprising cationic surfactants.
It is also known to incorporate cationic polyamine dye-fixing agents into detergent compositions, as described in EP-A-462806.
However, formulations containing such polyamines exhibit poor stain removal properties as they tend to coat fabric surfaces thus trapping any stains on the fabric surface. Use of anionic surfactants to solve this problem may promote dye fading. The Applicants have found that this problem can be alleviated by the use of a cationic surfactant in combination with the cationic polyamine dye-fixing agents.
Furthermore, it is believed that following breakdown of an oily soil by the enzyme, the cationic surfactants used in the present invention may form complexes with the fatty acids and any other negatively charged breakdown product produced, increasing their solubility and enhancing greasy, oily soil removal and overall cleaning performance, prior to deposition of the dye-fixing agents.
All documents cited in the present description are incorporated herein by reference.